Lay-driving mechanism for looms



April 1, 1930. w. w. ROBERT'SON 1,752,459

LAY DRIVING MECHANISM FOR LOCMS Filed March 15, 1928 2 Sheets-Sheet l Tie-I m N R [Fire/2Z4 April 1, 1930. w. w. ROBERTSON 1,752,459

LAY DRIVING MECHANISM FOR LOOMS Filed March 15, 1928 2 Sheets-Sheet 2 Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE WILLIAM W. ROBERTSON, F WORCESTER, MASSACHUSETTS, ASSIGNOR TO CROMPTON & KNOWLES LOOM WORKS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS LAY-DRIVTNG MECHANISM FOR LOOMS Application filed March 15, 1928. Serial No. 261,992.

This invention relates to mechanism for oscillating the lay in a wide loom designed for weaving carpet or other heavy fabric. In many such looms it is necessary to apply power to the lay at the ends only, and it is diflicult to prevent flexing or rearward yielding of the middle portion ofthe lay as the reed engages the fell of the cloth during 7 the beat-up.

It is the object of my invention to provide improved auxiliary mechanism at one or more intermediate points in the length of the lay, effective to positively advance the middle portion of the lay, particularly during the beating-up of the fabric.

A further object is to provide auxiliary mechanism so designed that the space below the harnesses will be left substantially free and unobstructed.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a sectional side elevation of portions of a loom embodying my improvements;

Fig. 2 is a rear elevation of the lay and certain associated parts;

Figs. 3, 4 and are sectional side elevations, taken along the lines 3-3, 44 and 5-5 but showing the parts in different relative positions; and

Fig. 6 is a detail sectional plan view, taken along the line 66 in Fig. 4.

Referring to the drawings, I haveshown portions of a loom frame 10 having a lay 11 mounted on swords 12 pivoted to a shaft 13 mounted in fixed hearings in the lower part of the loom frame. Each lay sword is actuated by toggle links 14 and 15, the link 14 a continually rotatingcrankshaft 21.

As the shaft rotates, the links 14 and 15 are forced upward, advancing the lay until they 3 I pass the dead center and then slightly withdrawing the lay as they move upward beyond dead center. On the ensuing downward movement, the lay is again advanced, thus giving the double beat effect essential for the satisfactory operation of looms for weaving velvet or Wilton carpet or using cross wires for cutting the pile.

The parts thus far described are of the usual type and form no part of my present invention, which relates particularly to means for positively advancing the middle portion of the lay 11. For this purpose I provide an auxiliary shaft extending across the loom parallel to the lay and supported in fixed hearings in the loom frame 10. Gears 26 are keyed to the end of the shaft 25 and are each engaged by the teeth of a rack plate 28 secured to the side of a bracket or forward projection 29 on one of the lay swords 12.

Each plate 28 is clamped in position by a binding screw 30 and lock nut 31 and may be additionally secured by bolts 32. Shims or packing may be placed at the front end of each rack plate for adjusting its position. The rack plates 28 are thus mounted to move positively with the lay swords 12 and through their engagement with the gears 26 they positively rotate the auxiliary shaft 25.

The shaft 25 is provided with one or more additional gears 35, keyed to the shaft 25 at intermediate positions in the length of the shaft. These gears 35 are similarly engaged by rack plates 36 (Fig. 5) firmly secured to intermediate or auxiliary swords 37 supporting the lay 11 at one or more intermediate points.

As the end swords 12 are positively advanced by the toggle links 14 and 15, the rack plates 28 on the swords 12 positively rotate the shaft 25, which in turn positively moves the rack plates 36 and associated auxiliary swords 37 forward, thus causing the middle portions of the lay 11 to be advanced simultaneously and in exact alignment with the end portions of the lay and thus strongly reinforcing the lay at the time of heat-up, when the strain on the lay is the greatest.

Thile the mechanism thus far describedis ordinarily effective for the purposes designed, the auxiliary shaft in an unusually wide and heavy loom is subject to a twisting strain which may permit the middle portions of the lay to lag slightly behind the end portions. Accordingly I have provided additional mechanism for giving the middle portion of the lay its final advance movement at the time of beat-up.

For this purpose, I provide one or more cylindrical members 40 keyed to the auxiliary shaft in the middle portions thereof. Each of these members 40 has a portion thereof cut away to provide a radially disposed K shoulder 41 (Figs. 1 and 3) adapted to be engaged by a lug or projection 42 on the end of the offset arm 43 of an auxiliary clamping lever 44:. The lever ll is mounted on a fixed pivot 45 1) supported by a bracket 16 on a cross beam 4:? forming a part of the loom frame 10.

The lower end of the lever 44: is connected by an adjustable link to the depending arm of a lever 51 pivoted on a fixed bracket 53 and having a cam roll 54 at its upper end, positioned to engage a double pointed cam 55 secured to the crankshaft 21 pre viously described.

The two points of the cam 55 correspond in angular relation to the successive positions of the cranltpin 20 when the toggle arms 14 and 15 are on dead center and the lay is at its extreme forward limit of movement. A spring 56 holds the lower end of the lever 1 i normally forward, with the lug 42 raised out of the path of the cylindrical member 40.

The shaft 25 is thus normally free to rotate under the action of the rack plates 28 as previously described, but as the lay ap proaches front center, the cam roll 54 is engaged by one of the projections of the cam 55, rocking the levers 51 and 4A and swinging the projection 42 on the lever 1 1 downward to positively engage the shoulder 41 on the member 40, thus giving the shaft a final movement to a predetermii'ied and definite final angular position as the lay reaches front center.

The cam roll 20 then passes off of the first high point of the cam, allowing the shaft 25 to rotate in the opposite direction as the lay is backed off by the continued upward movement of the toggle arms, but as the lay again moves forward the second high point of the cam 55 engages the roll 20 and again acts through the levers 51 and 414i and projection 42 to turn the shaft 25 a second time to its predetermined final angular position.

By increasing the number of the cylindrical members 40 and the cam and lever mechanism asmciated therewith, positive rotation of the shaft 25 may be insured at all intermediate points, regardless of the length of the shaft. It will. be 1 Jted, also that the connections between the cam 55 and the lever 44: are

so disposed that the space below the harness is entirely free and unobstructed substantial ly to the level of the floor on which the machine rests, a particularly desirable feature in. a carpet loom where the so-called lingos or Jacquard cords and weights occupy much space below the harnesses.

Having thus described my invention and the advantages thereof I do not wish to be imited to the details herein disclosed otherwise than as setforth in the claims, but what I claim is n 1. In a loom, a lay, means to move the end portions of said lay positively forward to beat up the cloth, and simultaneously acting means to move the middle portion of said lay positively forward, said latter means being operative only at the beat up.

2. In a loom, a lay, supports therefor, means to move the end portions of said lay positively forward to beat up the cloth, and auxiliary means effective to move the middle portion of said lay forward, said auxiliary means being actuated by devices projecting forward from the front sides of said lay end portions and said auxiliary means including a transversely extending member operatively connected to said forwardly extending devices and also to the middle portion of the lay.

3. In a loom, a lay, means to move the end portions of said lay positively forward to beat up the cloth, and operative connections through which power is transmitted direct from said moving means to positively advance the middle portion of the lay simultaneously therewith, said connections being normally inoperative and becoming operative as the lay approaches the beat up.

i. In a loom, a lay, means to positively advance the end portions thereof, an auxiliary shaft mounted in fixed bearings and extending across the loom in front of and parallel to said lay, gears on said shaft at the ends thereof and at a middle portion thereof, driving racks movable with said. lay and engaging said end gears, and a rack as sociated with the middle portion of said lay and positively moved by said middle gear.

5. In aloom, a lay, means to positively advance the end portions thereof, an auxiliary shaft mounted in fixed bearings and extending across the loom in front of and parallel to said lay, driving connections engaging the ends of said shaft and effective to positively rotate said shaft in alternate directions as the lay oscillates, and a driving connection between said shaft and a middle portion of said lay by which said middle portion is positively drawn forward simultaneously with the forward movementof said end portions of said lay.

6. The combination in a loom as set forth in claim 5, in which an additional postively moved member engages said auxiliary shaft at a middle portion thereof and advances said shaft to a predetermined angular position as the lay reaches front center.

7. The combination in a loom as set forth in claim 5, in which said auxiliary shaft is provided with a shoulder in a middle portion thereof and in which cam operated means engages said shoulder and positively advances said shaft to a predetermined angular position as the lay reaches front center.

8. The combination in a loom as set forth in claim 5, in which said auxiliary shaft is provided with a shoulder in a middle portion thereof and in which cam operated means engages said shoulder and positivelyadvances said shaft to a predetermined angular position as the lay reaches front center, said cam operated means being otherwise out of the path of movement of said shoulder.

9. The combination in a loom as set forth in claim 5, in which said auxiliary shaft is provided with a shoulder in a middle portion thereof, and in which driving means engages said shoulder and positively advances said shaft to a predetermined angular position as the lay reaches front center, said driving means including a lever mounted on a fixed pivot and having a portion adapted to engage said shoulder as the lay approaches front center and a continually rotating cam connected to move said lever intermittently.

10. The combination in a loom as set forth in claim 5, in which said auxiliary shaft is provided with a member secured to a middle portion thereof and having a shoulder thereon, and in which driving means engages said shoulder and positively advances said shaft to a predetermined angular position as the lay reaches front center, said driving means comprising a cam on the crankshaft of the loom, a lever engaged by said cam, a second lever mounted on a second fixed pivotand having an offset projection adapted to engage the shoulder on said member as the lay approaches front center, and a link connecting the depending arm of said first lever to the lower end of said second lever, said link being below the path of movement of the loom harnesses.

In testimony whereof I have hereunto affixed my signature.

WILLIAM W. ROBERTSON. 

